Sensory-Motor Processing during Sleep

Abstract Sleep is characterized in humans and other mammals by specific body postures indicative of a gradual decrease in motor activity, and by an elevated arousal threshold that reduces the likelihood of an external stimulus to cause arousal. In this chapter, we describe how sensory and motor processing are modulated in sleep. Despite an elevated arousal threshold, sensory processing remains active, allowing for the perception of important stimuli such as a baby’s cry or one’s name. This processing is supported by ongoing activity in sensory pathways, even during deep non–rapid eye movement (NREM) and rapid eye movement (REM) sleep stages. Motor processing is strongly modulated by sleep, with overall motor activity and reflexes decreased to prevent unnecessary movements. In this chapter, we discuss how disruption of sensory-motor processing underlies specific sleep disorders, such as REM sleep behavior disorder (RBD), restless legs syndrome (RLS), periodic limb movement disorder (PLMD), and obstructive sleep apnea (OSA).